Abstract ? Vector-Borne Diseases Core The Vector-Borne Diseases Core produces tick vectors for research on Lyme disease and other tick-borne diseases. All of the developmental stages of the hard tick Ixodes scapularis are available for research purposes. The Core is run by Mary Jacobs, MS, under the direction of Monica Morici-Embers, PhD. During the last funding period, the Core made useful improvements to the techniques of tick feeding on animals. These changes facilitated the use of xenodiagnosis, a procedure that is very sensitive for detection of living spirochetes in animals with low-level infections. The types of services provided include the provision of ticks for: 1) Tick- mediated infection, 2) Capillary feeding of ticks, 3) Xenodiagnosis, and 4) Collection of tick saliva. All of the service capabilities of the Core were utilized this funding period, and a large number of ticks (6720) were generated. The Core has been very productive and has fostered a large number of collaborations.